MONO_L            185 libavfilter/vf_stereo3d.c     { "ml",    "mono left",                           0, AV_OPT_TYPE_CONST, {.i64=MONO_L},             0, 0, FLAGS, "out" },
MONO_L            444 libavfilter/vf_stereo3d.c     case MONO_L:
MONO_L            567 libavfilter/vf_stereo3d.c     case MONO_L: